The first phase of reactor tests of the Russian accident-free nuclear fuel was held at Rosatom. This was reported by the fuel company TVEL, which is part of the corporation.
Tests of two experimental fuel assemblies (FAs) used as a source of energy in nuclear reactors took place at the SSC of the Scientific Research Institute of Atomic Reactors (NIIAR) in Dimitrovgrad, Ulyanovsk Region.
The experiment was conducted in the MIR research reactor since January 2019. Inspection of the experimental fuel assemblies used during this period was carried out by the specialists of JSC “High-Tech Research Institute of Inorganic Materials named after Academician A.A. Bochvara. "
“Their preliminary inspection, performed by specialists of VNIINM named after A.A. Bochvara, did not reveal any changes in the geometry of the fuel rods, nor damage to the surface of the shells. Several fuel elements from each fuel cartridge were extracted for further post-reactor material science research, the results of which will help determine the optimal combination of materials. Instead of the removed fuel rods, new non-irradiated samples were inserted into the fuel cartridges for further testing in the MIR reactor, ”the TVEL statement said.
Fuel elements - fuel elements that contain nuclear fuel - provide heat removal from the fuel to the coolant and prevent radioactive products from entering it. They are a tube filled with tablets of nuclear fuel.
The fact that trouble-free fuel was developed in Russia became known in December last year. At the same time, TVEL reported that the experimental fuel assemblies passed factory tests and acceptance of the industry commission.
Resistance to severe accidents of nuclear power plants
Trouble-free, or tolerant, fuel is resistant to severe accidents at nuclear power plants. Its peculiarity is that if problems arise during heat removal, it can maintain integrity for a long time without the appearance of a steam-zirconium reaction - a chemical interaction between water or its substitute with zirconium used in fuel.
The steam-zirconium reaction can lead to the destruction of the reactor and the release of radioactive substances into the environment. This reaction occurs at a vapor temperature above 861 ° C.
“Even in the event of a violation of heat removal in the core, the tolerant fuel must maintain integrity for a sufficiently long time without the occurrence of a steam-zirconium reaction, which promotes the evolution of hydrogen. The introduction of emergency fuel is of key importance to bring system safety and reliability of nuclear power to a whole new level, ”the TVEL website said.
Next year, tests can be carried out at an existing Russian nuclear power plant, said Alexander Ugryumov, Vice President for TVEL, TVEL.
“The project of creating Russian tolerant fuel is moving according to plan. In 2020, we intend to expand the program of reactor tests and load a batch of experimental fuel assemblies with separate fuel elements in a “tolerant” version at one of the Russian nuclear power plants with VVER-1000 reactors. In addition, in the future we can consider the use of promising new materials for fuel pellets and fuel claddings, ”the company’s website quotes him.
Note that in Russia there are several nuclear power plants equipped with VVER-1000 - these are Novovoronezh, Kalinin, Balakovo and Rostov.
RIA Novosti with reference to the procurement site of Rosatom reports that tests can be arranged at one of the units of the Rostov NPP. It is noted that the Research Institute "Kurchatov Institute" will carry out work to substantiate the safety of experimental fuel assemblies.
- © Sergey Pivovarov / RIA News
The most significant accidents at nuclear power plants occurred precisely because heat transfer was interrupted, Igor Yushkov, a leading expert at the National Energy Security Fund, a lecturer at the Financial University under the Russian government, said in a conversation with RT.
“New developments increase the reliability of nuclear power plants, because all the major, recent, recent decades of accidents mainly occurred due to the fact that, as a rule, the power supply was interrupted, that is, the safety systems could not function. In particular, this happened at Fukushima: that is, a tsunami and an earthquake caused the station to be de-energized and, accordingly, the backup power was at the bottom, the generators flooded and they did not work. Therefore, the station was de-energized and the security system could not function. Accordingly, the fuel was heated to a certain level and, as a result, melted, ”he explained.
According to Yushkov, Russian specialists are working to ensure that in the event of such accidents, NPP employees have more time to restore the plant's security systems.
“Now Rosatom’s nuclear plants are designed for large and powerful earthquakes, they will stand up and nothing will happen to the reactor. Designed for the direct hit of aircraft in the building of a nuclear power plant - all this has already been incorporated into the safety system of nuclear power plants. That is, safety is the main question, if you answer it and guarantee safety, then nuclear energy will have a future, ”said the analyst.
Note that the tests were carried out with fuel rods suitable for both VVER and PWR reactors common in foreign countries. In PWR, tetrahedral bundles of fuel elements are used, while in VVER, hexagonal bundles are used.
According to Rosatom, Russia occupies 17% of the entire nuclear fuel market. The corporation is one of the leaders in the field of nuclear energy, said Yushkov. According to the analyst, in recent years it has been increasing competition in foreign markets.
“That is, it’s not just building nuclear plants of our type in other countries in our reactors, but also in those countries where Western companies built nuclear reactors, it enters the fuel market. That is, it knows how to make fuel assemblies that are suitable for foreign reactors. Therefore, they say in Rosatom that they will ensure safety not only at Russian reactors, but they can also guarantee this safety to all others, ”he emphasized.
France can make relative competition in a number of positions of Russia, however, in general, Russian technologies are more advanced and efficient, said Alexander Frolov, Deputy Director General of the Institute of National Energy, in a conversation with RT.
“Developments from uranium enrichment to specific reactor designs in our country are the most advanced, most innovative of what in principle is in the world. Of course, according to a number of parameters, as far as I know, some other countries can compete with us, and some other countries successfully compete, say France. But it is worth noting that, in terms of a combination of factors, the Russian nuclear industry is absolutely the most widespread and most innovative in the world, ”the analyst said.